Method of mounting parts

ABSTRACT

In a parts mounting method having plural parts feed units, for setting aside a parts feed unit at a refill position if running short of a certain part in the process of mounting parts, and continuing parts mounting in other parts feed units, it is intended to reduce production stops due to parts shortage, and enhance the operation rate of the mounting machine. To achieve the object, the method of the invention comprises a step of judging if parts are refilled in the parts feed unit  4 R at the refill position when parts shortage occurs while mounting parts in the parts feed unit  4 L, a step of judging if all parts feed units  4 L,  4 R are out of the parts which are in shortage if parts are not refilled, and a step of mounting parts from the parts feed unit  4 R at the refill position if shortage parts are present in the parts feed unit  4 R at the refill position.

TECHNICAL FIELD

The present invention relates to a parts mounting method in a mountingmachine of electronic parts or the like.

BACKGROUND ART

Recently, along with the advancement of electronics revolution, furtherenhancement of productivity is also required in electronic partsmounting machines. Conventional electronic parts mounting machines aredescribed below while referring to FIG. 2, FIG. 3, and FIG. 4.

FIG. 2 shows a schematic constitution of an electronic parts mountingmachine. Reference numeral 1 denotes a rotary head, which mounts partsby means of plural nozzles 2. Reference numeral 3 denotes an X-Y table,which fixes a board to mount parts on, and positions the board beneaththe nozzles 2. Reference numerals 4L, 4R are parts feed units, andplural parts cassettes (parts feed means) 5 are mounted on each onethereof, and desired parts cassettes are positioned beneath the nozzles2. Reference numeral 7 denotes a controller, which controls the entireelectronic parts mounting machine. Reference numeral 10 is an indicatorwarning the shortage of parts to the operator, 11 is board carryingmeans, and 12 is board discharge means.

Referring now to FIGS. 3(a)(1), 3(a)(2) and 3(b)(1) to 3(b)(3), theoperation of parts feed units 4L, 4R (hereinafter shown merely as L andR) is described. FIGS. 3(a)(1) and 3(a)(2) show the configuration ofparts cassettes 5 in the parts feed units L, R. Both parts feed units L,R are in completely identical parts layout. This is intended to continueproduction by other parts feed unit R or L if parts are used up duringproduction in one parts feed unit L or R. FIGS. 3(b)(1) and 3(b)(3) showthe motion of the parts feed units L, R in the event of parts shortageduring production. In the state shown in FIG. 3(b)(1), the parts feedunit L is in the process of production in the active position, while theparts feed unit R is located at the parts refill position notinterfering the parts feed unit L. Herein, when parts shortage occurs,it is changed to the state shown in FIG. 2(b)(2). That is, the partsfeed unit L moves to the parts refill position, and the parts feed unitR moves to the active position to continue production. The operatorrefills the parts feed unit L. When further parts shortage occurs, thestate becomes as shown in shown in FIG. 3(b)(3). That is, the parts feedunit R moves to the parts refill position, and the parts feed unit Lmoves to the active position to continue production. By thus exchangingthe parts feed units L and R, drop of operation rate due to partsshortage is prevented.

The conventional parts mounting method employing such plural parts feedunits is specifically described below by referring to the flowchart inFIG. 4. Parts are sucked to the nozzles 2 from the parts feed unit L(step #101), and it is judged if there are parts or not (step #102), andif there are parts, parts are mounted on a board fixed on the X-Y table3 (step #103). It is then checked if all parts to be mounted on theboard by this mounting machine are completely mounted (hereinaftercalled EOP) or not (step #104), and the operation of steps #101 to #103is repeated until reaching the EOP. When reaching the EOP, the mountedboard is discharged, and next board is sent in (step #105).

On the other hand, if shortage of parts is detected at step #102, theparts feed unit L is moved to the refill position (step #106), andproduction is continued by the parts feed unit R (steps #107 to #111).Herein, steps #107 to #111 are same in processing as steps #101 to #105.In the midst of steps #107 to #111, if parts shortage occurs at step#108, the parts feed unit R is moved to the refill position (step #112),and it is judged if the parts feed unit L running short of parts in thefirst place is still in the process of parts refill or not (step #113),and if it is in the process of parts refill, production is stopped dueto parts shortage (step #121), or if parts refill has been complete,going back to step #101, production is continued in the parts feed unitL.

In such mounting method, however, unless parts are refilled immediatelyby the operator, both the parts feed units L and R may be out of parts,and production may be stopped, so that the operation rate may decline.In particular, in the nighttime when the number of workers is small, itwas difficult to operate continuously for a long time.

DISCLOSURE OF THE INVENTION

In the light of the problems of the prior art, it is hence a primaryobject of the invention to present a parts mounting method capable ofdecreasing productions stops due to parts shortage, operatingcontinuously for a long time, and enhancing the operation rate of themounting machine.

The parts mounting method of the invention is a parts mounting methodfor mounting parts by selectively using plural parts feed units,comprising a step of checking for shortage of same parts in plural partsfeed units when parts shortage occurs, and a step of feeding parts froma parts feed unit not running short for mounting parts.

The invention also presents a parts mounting method, having plural partsfeed units, for setting aside a parts feed unit at a refill position ifrunning short of a certain part in the process of mounting parts, andcontinuing parts mounting in other parts feed units, comprising a stepof judging if parts are refilled in the parts feed unit at the refillposition when parts shortage occurs while mounting parts, a step ofjudging if all parts feed units are out of the parts which are inshortage if parts are not refilled, and a step of mounting parts fromthe parts feed unit at the refill position if shortage parts are presentin the parts feed unit at the refill position.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart of a parts mounting method in an embodiment of theinvention.

FIG. 2 is a perspective view showing a schematic constitution of anelectronic parts mounting machine.

FIGS. 3(a)(1), 3(a)(2) and 3(b)(1) to 3(b)(3) are operation explanatorydiagrams in the event of parts shortage at a parts feed unit in the sameelectronic parts mounting machine.

FIG. 4 is a flowchart of parts mounting method in a prior art.

BEST MODE OF CARRYING OUT THE INVENTION

According to the parts mounting method of the invention, in the event ofparts shortage, all of plural parts feed units are judged if the sameparts are running short, if the same parts are not running out in anyparts feed unit, the parts are supplied from such parts feed unit tomount parts, so that the production is not stopped if the productionefficiency is lowered somewhat for exchanging the parts feed units, andthe parts can be mounted continuously, so that the operation rate of theparts mounting machine may be enhanced.

An embodiment of parts mounting method of the invention is describedwhile referring to FIG. 1. The constitution of the parts mountingmachine is same as the one shown in FIG. 2 relating to the prior art,and its description is omitted.

The parts mounting method is explained by referring to the flowchart inFIG. 1. Parts are sucked to the nozzles 2 from the parts feed unit L(step #1), and it is judged if there are parts or not (step #2), and ifthere are parts, parts are mounted on a board fixed on the X-Y table 3(step #3). It is then checked if all parts to be mounted on the board bythis mounting machine are completely mounted (hereinafter called EOP) ornot (step #4), and the operation of steps #1 to #3 is repeated untilreaching the EOP. When reaching the EOP, the mounted board isdischarged, and next board is sent in (step #5).

If running out of parts at step #2, the parts feed unit L is moved tothe refill position (step #6), and production is continued by the partsfeed unit R (steps #7 to #11). Herein, steps #7 to #11 are same inprocessing as steps #1 to #5. In the midst of steps #7 to #11, if partsshortage occurs at step #8, the parts feed unit R is moved to the refillposition (step #12), and it is judged if the parts feed unit L runningshort of parts in the first place is still in the process of partsrefill or not (step #13). If parts refill has been complete, going backto step #1, production is continued in the parts feed unit L (steps #1to #5).

On the other hand, by the judgement at step #13, if parts refilling isnot complete yet in the parts feed unit L first running out of parts, itis judged if the parts running out in the parts feed unit L and theparts running out in the parts feed unit R are same or not (step #14),and if same, the parts cannot be mounted, and the production is stoppeddue to parts shortage (step #21). By contrast, if judged to be differentparts at step #14, parts are selectively sucked from both parts feedunits L and R (step #15). For example, in FIG. 3, if parts A are used upin the parts feed unit L and parts B are used up in the parts feed unitR, as far as there are parts B and parts A respectively in the partsfeed units L and R, parts necessary for production are present in theparts feed units, and it is not necessary to stop production, andtherefore the parts B are sucked from the parts feed unit L and the partA, C to N from the parts feed unit R. Next, judging if the parts arepresent or running out (step #16), and if running out of parts, same asin step #14, it is judged if there are corresponding parts in the otherparts feed unit (step #20), and if there are parts, going back to step#15, production is continued, and if parts are not available, shiftingto step #21, production is stopped due to parts shortage. Or, if thereare parts by the judgement at step #16, parts are mounted on the boardfixed on the X-Y table 3 (step #17), and it is judged if all parts to bemounted on the board by this mounting machine are mounted (hereinaftercalled EOP) or not (step #18), and the operation of steps #15 to #17 isrepeated until reaching the EOP. When reaching the EOP, the mountedboard is discharged, and a next board is sent in (step #19).

Thus, according to the embodiment, even in the case where production isstopped due to parts shortage in the prior art, production can becontinued without stopping.

INDUSTRIAL APPLICABILITY

Thus, according to the parts mounting method of the invention, in theevent of parts shortage, all of plural parts feed units are judged ifthe same parts are running short, if the same parts are not running outin any parts feed unit, the parts are supplied from such parts feed unitto mount parts, so that the production is not stopped if the productionefficiency is lowered somewhat for exchanging the parts feed units, andthe parts can be mounted continuously, so that the operation rate of theparts mounting machine may be enhanced.

What is claimed is:
 1. A method of mounting parts via a mounting machinehaving a plurality of parts feed units, said method comprising steps of:providing each one of said plurality of parts feed units with a firstcassette including a plurality of first parts and a second cassetteincluding a plurality of second parts, (a) when a shortage of saidplurality of first parts occurs in said first cassette of one of saidplurality of parts feed units, checking whether or not a shortage offirst parts exists in any other parts feed units of said plurality ofparts feed units other than said one of said plurality of parts feedunits, (b) when a result of checking is that of a non-shortage of saidfirst parts in at least one of said plurality of parts feed units,mounting at least one of said first parts from said at least one of saidplurality of parts feed units, and (c) when a result of checking is thatof a shortage of said first parts in said plurality of parts feed units,stopping mounting said first parts.
 2. The method of claim 1, furthercomprising a step of: (d) when said shortage of said plurality of firstparts occurs in said first cassette of one of said plurality of partsfeed units, setting said one of said plurality of parts feed units to arefill position and refilling first parts into said first cassette ofsaid one of said plurality of parts feed units.
 3. The method of claim1, further comprising a step of: (e) when said first parts are notpresent in each one of said plurality of parts feed units, stoppingmounting said parts.
 4. The method of claim 1, wherein step (b) furthercomprises a step of: refilling said first cassette of step (a) with newfirst parts while mounting the at least one of said first parts fromsaid at least one of said plurality of parts feed units.
 5. The methodof claim 1, further including a step (bc) between steps (b) and (c),said step (bc) includes: when a shortage of said plurality of secondparts occurs in said second cassette of another one of said plurality ofparts feed units, checking whether or not a shortage of said secondparts exists in any other parts feed units of said plurality of partsfeed units, when a result of checking is that of a non-shortage of saidsecond parts in at least one of said plurality of parts feed units,mounting at least one of said second parts from said at least one ofsaid plurality of parts feed units.
 6. A method of mounting partscomprising steps of: providing a plurality of feed units; providing eachfeed unit with a plurality of parts, said plurality of parts includingfirst and second parts; a) mounting said plurality of parts from one ofsaid plurality of feed units until said first parts are exhausted; b)refilling said one of said plurality of feed units with said firstparts; c) mounting said plurality of parts from another of saidplurality of feed units until said second parts are exhausted; d)repeating anew steps a)-c) if said first parts during step b) areavailable, wherein if said first parts are not available from step b)then, 1) determining if said first parts are a same type of parts assaid second parts.
 7. The method of claim 6, further including a stepof: (e) mounting at least one of said second parts from said one of saidplurality of feed units of step (a) if said first parts are not the sametype of parts as said second parts.
 8. A method of mounting partscomprising steps of: providing a plurality of feed units, said pluralityof feed units including first and second feed units; providing each feedunit with a plurality of parts, said plurality of parts including firstand second parts; (a) when a shortage of said first parts of saidplurality of parts occurs in one of said first feed units of saidplurality of feed units, checking whether a shortage of said secondparts of said plurality of parts exists in all other parts feed units ofsaid plurality of parts feed units other than the one of said first feedunit; and (b) when a result of checking is that of a non-shortage ofsaid second parts in at least one of said all other parts feed unitsother than the one of said first feed unit, mounting at least one ofsaid second parts.
 9. A method of mounting parts comprising steps of:providing a plurality of feed units, said plurality of feed unitsincluding first and second feed units; providing each feed unit with aplurality of parts said plurality of parts including first and secondparts; (a) when a shortage of said first parts of said plurality ofparts occurs in one of said first feed units of said plurality of feedunits, mounting a same type of part as said first parts from one of saidsecond feed units of said plurality of feed units, and (b) when ashortage of said second parts of said plurality of parts occurs in oneof said second feed units of said plurality of feed units, mounting asame type of part as said second parts from one of said first feed unitsof said plurality of feed units.
 10. A method of mounting parts by amounting machine, said mounting machine comprising a first parts feedunit (L) having a first cassette containing a first set of plurality offirst parts (A) and a second cassette containing a first set ofplurality of second parts (B), and a second parts feed unit (L) havingother first cassette containing a second set of said plurality of firstparts (A) and other second cassette containing a second set of saidplurality of second parts (B), said method comprising steps of: (a) whenshortage occurs in said first parts (A) in the first cassette of saidfirst parts feed unit, and further shortage occurs in said second parts(B) in said other second cassette of said second parts feed unit,checking if said first parts (A) in said other first cassette of saidsecond parts feed unit are in shortage or not, and if said second parts(B) in said second cassette of said first parts feed unit are inshortage or not, (b) when the first parts (A) in said other firstcassette of said second parts feed unit are not in shortage as a resultof said checking, mounting said first parts (A) from said other firstcassette of the second parts feed unit, (c) when the second parts (B) insaid second cassette of said first parts feed unit are not in shortageas a result of said checking, mounting said second parts (B) from saidsecond cassette of the first parts feed unit, and (d) when said firstparts (A) in said other first cassette of said second parts feed unitare in shortage and further said second parts (B) in said secondcassette of said first parts feed unit are in shortage as a result ofsaid checking, stopping the mounting steps.